NORTHFIELD — No one was hurt, but two pets perished in a Thursday afternoon fire that gutted a home on Bear Farm Road.

The exact cause of the fire, which was reported by a passing motorist shortly before 1 p.m., has yet to be determined, though state fire investigators reportedly spent more than three hours at the scene Thursday.

Northfield Fire Chief Peter Demasi, who asked the state to investigate the origin and cause, declined to comment when asked if the fire was considered suspicious.

Demasi did say that by the time local volunteers arrived on the scene, not long after the fire was reported, the home was “fully involved.”

Members of four other departments — Barre, Berlin, Williamstown and Roxbury — were called in to assist, and Demasi said roughly 40 firefighters were on the scene at the height of the fire.

Although no one was home when the fire was reported, Demasi said owner Jeff Ott showed up not long after firefighters arrived. According to Demasi, Ott told firefighters that two pet dogs were inside, but by that point the dogs were presumed dead and the fire had progressed to the point where trying a rescue would have been impossible.

According to Demasi, water wasn’t an issue fighting the fire — it was trucked in by tanker from a dry hydrant on nearby Bean Road — but a 10 mph wind was.

He said the fire started in a story-and-a-half section of the home but, when “pushed” by the persistent wind, quickly spread into an attached two-story section that included a garage.

Demasi said it took roughly two hours to bring the blaze under control and the better part of an additional 90 minutes to fully extinguish it. It was out by about 4:30 p.m., he said.

However, Demasi said local firefighters remained on the scene to assist investigators and to make sure the fire didn’t rekindle until shortly before 8 p.m.

Demasi said the home and its contents were destroyed. A portion of the structure is still standing but was gutted by the fire.

Attempts to reach fire investigators for an update Friday were unsuccessful.